The Trump administration claimed on Monday that it may have identified a link between the use of a common painkiller during pregnancy and autism in children, prompting swift backlash from child health experts.
The announcement came months after US health secretary Robert F Kennedy Jr vowed to identify the cause of autism by September.
The US Food and Drug Administration (FDA) advised doctors to "consider minimising” pregnant women's use of paracetamol – a common painkiller that is also called acetaminophen and sold as Tylenol in the United States – amid concerns that it could raise the risk of autism.
But US President Donald Trump went further, claiming that Tylenol "is no good" and that pregnant women should "fight like hell" to avoid taking it. He had teed up the news over the weekend, saying “I think we found an answer to autism”.
The global scientific community disagrees.
“I am exceptionally confident in saying that no relationship exists” between paracetamol and autism, said Dr Monique Botha, an associate professor in social and developmental psychology at Durham University in the United Kingdom.
Some studies suggest a potential link between paracetamol use early in pregnancy and slightly higher rates of autism in children, but they are inconclusive and do not prove the drug causes autism.
Other major studies also appear to refute these findings.
Last year, for example, Swedish researchers analysed data from nearly 2.5 million children born over a 24-year period to compare how siblings fared when their mothers used paracetamol.
They found that paracetamol use during pregnancy was not linked to children’s risk of autism, intellectual disabilities, or attention-deficit hyperactivity disorder (ADHD).
“This suggests that other factors, such as genetic or underlying maternal health conditions, may better explain the findings,” said Dr Hannah Kirk, a senior lecturer in the Turner Institute for Brain and Mental Health at Monash University in Australia.
Researchers believe autism is caused by a combination of genetic and environmental factors, such as advanced parental age, prenatal exposure to air pollution, and low oxygen around the time of birth, among others.
Advocacy groups such as Autism Speaks say that autism appears to be more common now than in the past due to increased awareness of the condition, improved screening, and changes to diagnostic criteria, leading to earlier detection and more children being diagnosed.
The FDA's new guidance acknowledges that there are "contrary studies" on the link between paracetamol and autism.
It says doctors should not regularly offer paracetamol to pregnant women with "routine low-grade fevers" but that any risks should be weighed against the fact that the medication is "the safest over-the-counter alternative in pregnancy" among common painkillers.
Even so, scientists warned that the guidance, and Trump's comments around it, could deter pregnant women from taking paracetamol to reduce fevers. High fever in pregnancy is considered a risk factor for neurodevelopmental disorders in children.
“Suggesting to pregnant women that this drug is unsafe will cause much anxiety to women who already feel vulnerable and overwhelmed with information,” said Dr Linden J Stocker, a fetomaternal medicine consultant at the University Hospitals Southampton in the UK.
Meanwhile, Botha warned that the announcement could stigmatise families with autistic children.
It “reinvigorates the long pattern of maternal shame and blame … where we try to pay the fault of autism at the mother's door one way or another,” Botha said.
Updated 23 September: This article was updated after the Trump administration made its announcement.
